Proof of Work & Mining

The last 2,016 blocks arrived faster than two weeks. What does the retarget do?

• Makes the target bigger, so blocks come even faster
• Makes the target smaller, so difficulty goes up and blocks slow back toward 10 minutes
• Nothing until a miner proposes a change

What may a miner pay itself in a block?

• Exactly the subsidy, never more
• Any amount the other miners agree to
• At most the subsidy plus the fees of the transactions in its block